[inspector] fix positions for single expression arrow function

src/parsing/parser-base.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PARSING_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
@@ skipping 2258 matching lines @@
   }
   initializer_scope->set_end_position(scanner()->location().end_pos);
   typename Types::StatementList body = impl()->NewStatementList(1);
   body->Add(factory()->NewReturnStatement(value, kNoSourcePosition), zone());
   FunctionLiteralT function_literal = factory()->NewFunctionLiteral(
       impl()->EmptyIdentifierString(), initializer_scope, body,
       initializer_state.materialized_literal_count(),
       initializer_state.expected_property_count(), 0, 0,
       FunctionLiteral::kNoDuplicateParameters,
       FunctionLiteral::kAnonymousExpression, default_eager_compile_hint_,
-      initializer_scope->start_position());
+      initializer_scope->start_position(), true);
   function_literal->set_is_class_field_initializer(true);
   return function_literal;
 }
 
 template <typename Impl>
 typename ParserBase<Impl>::ObjectLiteralPropertyT
 ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
                                                 bool* is_computed_name,
                                                 bool* ok) {
   bool is_get = false;
@@ skipping 1613 matching lines @@
   FunctionKind kind = formal_parameters.scope->function_kind();
   FunctionLiteral::EagerCompileHint eager_compile_hint =
       default_eager_compile_hint_;
   bool can_preparse = impl()->parse_lazily() &&
                       eager_compile_hint == FunctionLiteral::kShouldLazyCompile;
   // TODO(marja): consider lazy-parsing inner arrow functions too. is_this
   // handling in Scope::ResolveVariable needs to change.
   bool is_lazy_top_level_function =
       can_preparse && impl()->AllowsLazyParsingWithoutUnresolvedVariables();
   bool should_be_used_once_hint = false;
+  bool has_braces = true;
   {
     FunctionState function_state(&function_state_, &scope_state_,
                                  formal_parameters.scope);
 
     function_state.SkipMaterializedLiterals(
         formal_parameters.materialized_literals_count);
 
     impl()->ReindexLiterals(formal_parameters);
 
     Expect(Token::ARROW, CHECK_OK);
@@ skipping 42 matching lines @@
         Consume(Token::LBRACE);
         body = impl()->ParseEagerFunctionBody(
             impl()->EmptyIdentifier(), kNoSourcePosition, formal_parameters,
             kind, FunctionLiteral::kAnonymousExpression, CHECK_OK);
         materialized_literal_count =
             function_state.materialized_literal_count();
         expected_property_count = function_state.expected_property_count();
       }
     } else {
       // Single-expression body
+      has_braces = false;
       int pos = position();
       DCHECK(ReturnExprContext::kInsideValidBlock ==
              function_state_->return_expr_context());
       ReturnExprScope allow_tail_calls(
           function_state_, ReturnExprContext::kInsideValidReturnStatement);
       body = impl()->NewStatementList(1);
       impl()->AddParameterInitializationBlock(
           formal_parameters, body, kind == kAsyncArrowFunction, CHECK_OK);
       ExpressionClassifier classifier(this);
       if (kind == kAsyncArrowFunction) {
         ParseAsyncFunctionBody(scope(), body, kAsyncArrowFunction,
                                FunctionBodyType::kSingleExpression, accept_IN,
                                pos, CHECK_OK);
         impl()->RewriteNonPattern(CHECK_OK);
       } else {
         ExpressionT expression = ParseAssignmentExpression(accept_IN, CHECK_OK);
         impl()->RewriteNonPattern(CHECK_OK);
-        body->Add(factory()->NewReturnStatement(expression, pos), zone());
+        body->Add(
+            factory()->NewReturnStatement(expression, expression->position()),
+            zone());
         if (allow_tailcalls() && !is_sloppy(language_mode())) {
           // ES6 14.6.1 Static Semantics: IsInTailPosition
           impl()->MarkTailPosition(expression);
         }
       }
       materialized_literal_count = function_state.materialized_literal_count();
       expected_property_count = function_state.expected_property_count();
       impl()->MarkCollectedTailCallExpressions();
     }
 
@@ skipping 22 matching lines @@
     PrintF("  [%s]: %i-%i (arrow function)\n",
            is_lazy_top_level_function ? "Preparse no-resolution" : "Full parse",
            scope->start_position(), scope->end_position());
   }
   FunctionLiteralT function_literal = factory()->NewFunctionLiteral(
       impl()->EmptyIdentifierString(), formal_parameters.scope, body,
       materialized_literal_count, expected_property_count,
       formal_parameters.num_parameters(), formal_parameters.function_length,
       FunctionLiteral::kNoDuplicateParameters,
       FunctionLiteral::kAnonymousExpression, eager_compile_hint,
-      formal_parameters.scope->start_position());
+      formal_parameters.scope->start_position(), has_braces);
 
   function_literal->set_function_token_position(
       formal_parameters.scope->start_position());
   if (should_be_used_once_hint) {
     function_literal->set_should_be_used_once_hint();
   }
 
   impl()->AddFunctionForNameInference(function_literal);
 
   return function_literal;
@@ skipping 1396 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H